American Journal of Epidemiology Advance Access published online on October 3, 2008
American Journal of Epidemiology, doi:10.1093/aje/kwn232
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Original Contribution |
Chronic Particulate Exposure, Mortality, and Coronary Heart Disease in the Nurses’ Health Study
Correspondence to Dr. Robin C. Puett, SC Cancer Prevention and Control Program, Department of Environmental Health Sciences, Department of Epidemiology and Biostatistics, University of South Carolina, 2221 Devine Street, Room 227, Columbia, SC 29208 (e-mail: rpuett{at}gwm.sc.edu).
Received for publication January 30, 2008. Accepted for publication July 10, 2008.
Adverse health effects of exposures to acute air pollution have been well studied. Fewer studies have examined effects of chronic exposure. Previous studies used exposure estimates for narrow time periods and were limited by the geographic distribution of pollution monitors. This study examined the association of chronic particulate exposures with all-cause mortality, incident nonfatal myocardial infarction, and fatal coronary heart disease (CHD) in a prospective cohort of 66,250 women from the Nurses’ Health Study in northeastern US metropolitan areas. Nonfatal outcomes were assessed through self-report and medical record review and fatalities through death certificates and medical record review. During follow-up (1992–2002), 3,785 deaths and 1,348 incident fatal CHD and nonfatal myocardial infarctions occurred. In age- and calendar-time-adjusted models, 10-µg/m3 increases in 12-month average exposures to particulate matter <10 µm in diameter were associated with increased all-cause mortality (16%, 95% confidence interval: 5, 28) and fatal CHD (43%, 95% confidence interval: 10, 86). Adjustment for body mass index and physical activity weakened these associations. Body mass index and smoking modified the association between exposure to particulate matter <10 µm in diameter and fatal CHD. In this population, increases in such exposures were associated with increases in all-cause and CHD mortality. Never smokers with higher body mass indexes were at greatest risk of fatal CHD.
air pollution; cohort studies; coronary disease; environmental exposure; incidence; particulate matter; risk factors
Abbreviations: CHD, coronary heart disease; CI, confidence interval; PM2.5, particulate matter <2.5 µm in diameter; PM10, particulate matter <10 µm in diameter